31521540220343 has 4 divisors (see below), whose sum is σ = 31522620531240. Its totient is φ = 31520459909448.

The previous prime is 31521540220337. The next prime is 31521540220351. The reversal of 31521540220343 is 34302204512513.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31521540220343 - 2¹² = 31521540216247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31521540220363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 540111680 + ... + 540170037.

It is an arithmetic number, because the mean of its divisors is an integer number (7880655132810).

Almost surely, 2^{31521540220343} is an apocalyptic number.

31521540220343 is a deficient number, since it is larger than the sum of its proper divisors (1080310897).

31521540220343 is a wasteful number, since it uses less digits than its factorization.

31521540220343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080310896.

The product of its (nonzero) digits is 86400, while the sum is 35.

Adding to 31521540220343 its reverse (34302204512513), we get a palindrome (65823744732856).

The spelling of 31521540220343 in words is "thirty-one trillion, five hundred twenty-one billion, five hundred forty million, two hundred twenty thousand, three hundred forty-three".